react怎么实现弹出模态框

import React, {useMemo, useEffect, useState} from 'react' import ReactDOM from 'react-dom' /**  *  * 需要把元素渲染到组件之外，用 createPortal 把元素直接渲染到 document.body 下，为了防止函数组件每一次执行都触发 createPortal， 所以通过 useMemo 做性能优化。  因为需要渐变的动画效果，所以需要两个变量 modelShow / modelShowAync 来控制显示/隐藏，modelShow 让元素显示/隐藏，modelShowAync 控制动画执行。  当弹窗要显示的时候，要先设置 modelShow 让组件显示，然后用 setTimeout 调度让 modelShowAync 触发执行动画。  当弹窗要隐藏的时候，需要先让动画执行，所以先控制 modelShowAync ，然后通过控制 modelShow 元素隐藏，和上述流程相反。  用一个控制器 controlShow 来流畅执行更新任务。  */ // 控制弹窗隐藏以及动画效果 const controlShow = (f1, f2, value, timer) => {     f1(value)     return setTimeout(() => {         f2(value)     }, timer) } export const Dialog = (props) => {     const {width, visible, closeCb, onClose} = props     // 控制 modelShow动画效果     const [modelShow, setModelShow] = useState(visible)     const [modelShowAsync, setModelShowAsync] = useState(visible)     const renderChildren = useMemo(() => {         // 把元素渲染到组件之外的document.body 上         return ReactDOM.createPortal(<div style={{display: modelShow ? 'block' : 'none'}}>             <div className="model_container" style={{opacity: modelShowAsync ? 1 : 0}}>                 <div className="model_wrap">                     <div style={{width: width + 'px'}}> {props.children} </div>                 </div>             </div>             <div className="model_container mast" onClick={() => onClose && onClose()}                  style={{opacity: modelShowAsync ? 0.6 : 0}}/>         </div>, document.body)     }, [modelShow, modelShowAsync])     useEffect(() => {         let timer         if (visible) {             // 打开弹窗，             timer = controlShow(setModelShow, setModelShowAsync, visible, 30)         } else {             timer = controlShow(setModelShowAsync,setModelShow,visible,1000)         }         return () => {             timer && clearTimeout(timer)         }     }, [visible])     return renderChildren }

import {Dialog} from "./Dialog"; import React, {useEffect, useState} from 'react' import ReactDOM from 'react-dom' import './style.scss' class Modal extends React.PureComponent {     // 渲染底部按钮     renderFooter = () => {         const {onOk, onCancel, cancelText, okText, footer} = this.props         //    触发onOk / onCancel回调         if (footer && React.isValidElement(footer)) return footer         return <div className="model_bottom">             <div className="model_btn_box">                 <button className="searchbtn"                         onClick={(e) => {                             onOk && onOk(e)                         }}>{okText || '确定'}                 </button>                 <button className="concellbtn"                         onClick={(e) => {                             onCancel && onCancel(e)                         }}>{cancelText || '取消'}                 </button>             </div>         </div>     }     // 渲染底部     renderTop = () => {         const {title, onClose} = this.props         return <div className="model_top">             <p>{title}</p>             <span className="model_top_close" onClick={() => onClose && onClose()}>X</span>         </div>     }     // 渲染弹窗内容     renderContent = () => {         const {content, children} = this.props         return React.isValidElement(content) ? content : children ? children : null     }     render() {         const {visible, width = 500, closeCb, onClose} = this.props         return <Dialog             closeCb={closeCb}             onClose={onClose}             visible={visible}             width={width}         >             {this.renderTop()}             {this.renderContent()}             {this.renderFooter()}         </Dialog>     } } // 静态方法 let ModalContainer = null const modelSymbol = Symbol('$$_model_Container_hidden') // 静态属性show——控制 Modal.show = (config) => {     //  如果modal已经存在，name就不需要第二次show     if (ModalContainer) return     const props = {...config, visible: true}     const container = ModalContainer = document.createElement('div')     // 创建一个管理者，管理model状态     const manager = container[modelSymbol] = {         setShow: null,         mounted: false,         hidden() {             const {setShow} = manager             setShow && setShow(false)         },         destroy() {             //    卸载组件             ReactDOM.unmountComponentAtNode(container)             // 移除节点             document.body.removeChild(container)             // 置空元素             ModalContainer = null         }     }     const ModelApp = (props) => {         const [show, setShow] = useState(false)         manager.setShow = setShow         const {visible, ...trueProps} = props         useEffect(() => {             // 加载完成，设置状态             manager.mounted = true             setShow(visible)         }, [])         return <Modal {...trueProps} closeCb={() => manager.mounted && manager.destroy()} visible={show}/>     }     // 插入到body中     document.appendChild(container)     // 渲染React元素     ReactDOM.render(<ModelApp/>, container)     return manager } Modal.hidden = () => {     if(!ModalContainer) return     // 如果存在ModalContainer 那么隐藏ModalContainer     ModalContainer[modelSymbol] && ModalContainer[modelSymbol].hidden() } export default Modal

$bg-linear-gradien-red-light : linear-gradient(135deg, #fc4838 0%, #f6346b  100%); $bg-linear-gradien-red-dark : linear-gradient(135deg, #fc4838 0%, #f6346b  100%); .constrol{   padding: 30px;   width: 500px;   border: 1px solid #ccc;   height: 200px; } .feel{   padding: 24px; } .model_top{   height: 40px;   border-radius: 5px  5px 0 0 ;   position: relative;   p{     height: 40px;     font-weight: bold;     line-height: 40px;     padding-left: 14px;   }   background-color: #eee;   .model_top_close{     position: absolute;     font-size: 16px;     cursor: pointer;     right: 24px;     top: 8px;   } } .model_bottom{   height: 50px;   padding-top: 10px;   .model_btn_box{     display: inline-block;     margin-left: 50%;     transform: translateX(-50%);   } } .model_container{   .model_wrap{     position: absolute;     border-radius:5px ;     background: #fff;     left:50%;     top:50%;     transform: translate(-50%,-50%);   }   position: fixed;   z-index: 10000;   left:0;   top:0;   transition: opacity 0.3s;   right: 0;   bottom: 0; } .mast{   background-color: #000;   z-index: 9999; } .searchbtn{   background: linear-gradient(135deg, #fc4838 0%, #f6346b  100%);   color: #fff;   min-width: 96px;   height :36px;   border :none;   border-radius: 18px;   font-size: 14px;   font-weight: 500;   cursor: pointer;   margin-left: 20px !important; } .searchbtn:focus{   background: $bg-linear-gradien-red-dark;   color: #fff;   min-width: 96px;   height: 36px;   border: none;   border-radius: 18px;   font-size: 14px;   font-weight: 500;   cursor: pointer;   margin-left: 20px !important;   box-shadow: 0 2px 7px 0 #FAA79B; } .searchbtn:hover{   background :$bg-linear-gradien-red-light;   color :#fff;   min-width: 96px;   height :36px;   margin-left: 20px !important;   border: none;   border-radius: 18px;   font-size :14px;   font-weight: 500;   cursor: pointer;   box-shadow: 0 2px 7px 0 #FAA79B; } .searchbtn:disabled{   background: #c0c6c6;   color :#fff;   min-width: 96px;   height :36px;   font-size :14px;   font-weight: 500;   border: none;   border-radius: 18px;   cursor: not-allowed; } .concellbtn{   background :#fff;   color :#303133;   width: 96px;   height: 36px;   font-size: 14px;   font-weight: 500;   border :1px solid #E4E7ED;   border-radius: 18px;   cursor: pointer;   // margin-right: 10px;   margin-left: 10px; } .concellbtn:hover{   background :rgba(220, 223, 230, 0.1);   color: #303133;   width :96px;   height: 36px;   font-size: 14px;   font-weight: 500;   border :1px solid #E4E7ED;   border-radius: 18px;   cursor: pointer;   // margin-right: 10px;   margin-left: 10px; } .concellbtn:focus{   background :rgba(220, 223, 230, 0.24);   color: #303133;   width :96px;   height: 36px;   font-size: 14px;   font-weight: 500;   border: 1px solid #C0C4CC;   border-radius: 18px;   cursor: pointer;   margin-right: 10px;   margin-left: 10px; }

import React, {useState, useMemo} from 'react' import Modal from './customPopup/Modal' /* 挂载方式调用modal */ export default function App() {     const [ visible , setVisible ] = useState(false)     const [ nameShow , setNameShow ] = useState(false)     const handleClick = () => {         setVisible(!visible)         setNameShow(!nameShow)     }     /* 防止 Model 的 PureComponent 失去作用 */     const [ handleClose ,handleOk, handleCancel ] = useMemo(()=>{         const Ok = () =>  console.log('点击确定按钮')         const Close = () => setVisible(false)         const Cancel = () => console.log('点击取消按钮')         return [Close , Ok , Cancel]     },[])     return <div>         <Modal             onCancel={handleCancel}             onClose={handleClose}             onOk={handleOk}             title={'标题'}             visible={visible}             width={700}         >             <div className="feel" >               内容。。。。。。。             </div>         </Modal>         <button onClick={() => {             setVisible(!visible)             setNameShow(false)         }}         > model show </button>         <button onClick={handleClick} > model show ( 显示作者 ) </button>     </div> }